Apparatus for developing crimps by heating composite filament



Filed Sept. 22, 1966 1969 MASAo MATSUI ETAL 3, 25,

APPARATUS 'FOR DEVELOPING CRIMPS BY HEATING COMPO SITE FILAMENT.

Sheet I oi 2 Feb. 4, 1969 MASAO MATSUI ETAL 3,425,107 APPARATUS FOR DEVELOPING CRIMPS BY HEATING COMPOSITE FILAMENT Filed Sept. 22, 1966- Sheet 2 of 2 United States Patent 40/ 62,551 US. Cl. 28-1 4 Claims Int. Cl. D02g 3/00; D021 13/00 ABSTRACT OF THE DISCLOSURE An apparatus for developing crimps in a composite filament in which the filament is fed into a heating zone at a given rate and withdrawn therefrom at a lesser rate. The filament is heated in the heating zone and then subjected to an air stream directed substantially perpendicular to the axis of the path of the crimped filament passing through said apparatus, the air stream maintaining a predetermined tension on the traveling filament.

The present invention relates to an apparatus for developing crimps by heating a composite filament obtained by bonding two polymers having different shrinking properties. A composite filament in which two components are eccentrically arranged in the cross-section can develop three-dimensional crimps by heating, but the factors which influence the crimp development are heating temperature and tension of the filament. Therefore, in order to obtain crimp filaments having uniform crimps and a good quality, it is necessary to control said temperature and tension exactly. It is, however, very difficult to maintain the filament tension at a constant value, particularly when composite filaments are continuously heated and crimped while traveling. This reason is based on the fact that it is necessary for the tension on the yarn to be extremely low (less than 0.1 mg./ d.) in order to develop crimps and in such a substantially tensionless condition there is a strong tendency to cause variations in tension.

The present invention provides an apparatus capable of maintaining a stable tension and hence developing a uniform crimp. The present invention consists in an apparatus for developing crimps in composite filaments by heating the composite filaments between feed rollers and delivery rollers while slackening them, characterized in that a suitable means for blowing air is provided on one end of the machine frame between a heater and the delivery rollers, by which air stream is blown to the traveling filaments from perpendicular direction thereto to subject a weak tension to the filaments.

For a better understanding of the invention, reference is taken to the accompanying drawings, wherein FIG. 1 is a side view, partially broken away, of an apparatus according to the present invention; and

FIG. 2 is a front view of the principal portion thereof.

Referring to the drawings, 2 denotes a raw filament from a pirn 1; 3 a tension device; 4 feed rollers; 5 a guide; 6 a heater; 7 a filament after developed crimps; 8 and 9 guides; 10 delivery rollers; 11 a traverse guide; 12 a winding roller; 13 a crimped yarn which has been wound; 14 a blower mounted on one end of the machine frame; 16 an air duct connecting to the delivery side of the blower; and an opening formed in said duct. The filament 7 which has developed crimps moves in an arcuate path in a direction of the air stream by means of the air stream from the blower 14 while it passes through the air duct, so that the filament is subjected to a weak tension.

In order to meet the object of the present invention, the range along which the traveling filament is blown by air from perpendicular direction to the filament is preferable to be 3 to 30 cm. in the length of filament and it is necessary to so arrange the air duct and the delivery opening. Further, it is necessary that the quantity of air blown against the filament should be so adjusted that the maximum distance between a straight line along which the yarn is passed in windless condition and an arch which the filament forms by air stream when blowing air, is greater than 2 mm. and less than 5 cm, preferably 5 mm. to 2 cm. More particularly, the blowing may be so effected as to meet particular objects depending upon the nature of composite filaments, heating conditions, filament velocity, filament diameter, etc.

The crimped filaments obtained by the use of the present apparatus are highly uniform, and since the tension when developing crimp can be maintained in a stable condition, it is possible to easily elfect the continuous operation of the apparatus for a prolonged period of time.

In the practice of the invention, nylon-6 having an intrinsic viscosity of 1.05 determined in metacresol solution at 30 C. and copolymer obtained by copolymerizing parts by weight of e-caprolactam and 10 parts of hexamethylenediammonium isophthalate in nitrogen atmosphere at 270 C. for 6 hours are melted and conjugate spun in a side-by-side type in a conjugate ratio of 1:1 and the resulting filaments were drawn in 3.9 times at room temperature to obtain composite multifilaments having 45 d./ 10 filament.

The composite filament was fed by the feed rollers at a feed rate (V of 63 m./min., and was heated by a contact type aluminum heater having a length of 15 cm. at C. of the surface temperature. Thereafter it was passed through the air duct 16 provided with the opening 15 having 0.5 cm. of width and 10 cm. of length and while air stream was fed to the filament from perpendicular direction thereto to provide a weak tension to the filament, the filament was delivered by the delivery rollers at a delivery rate V of 4S m./min. and was wound at a winding rate V of 48 m./min. The feed rate being V /V =1.31.5, the filament developed good crimps.

In case of simultaneously treating l8 filaments with the present apparatus, it was found that in 8 hour continuous operation without air blowing, 4 filaments were broken owing to the unsteadiness of the tension.

However, when air was blown in such a manner that the path of filament could be deviated 7 mm. at the maximum deviated point from a path of filament when air is not blown, the operation was very stable and the filament was not broken.

The filament breakage is mainly based on the fact that variations in the unwinding tension of raw filament pirns cause some variations in filament feeding rate and the fact that a slight variation of the shrinkability and crimpability of filament causes the filament to slacken and thereby to coil around rollers and other members. When the blowing means is working, a stable operation can be continued for a prolonged period of time, since if the cause of variation in tension occur the air stream and the filament are balanced with each other in such a manner that such causes are nullified.

When the crimped filaments obtained were used in knitted goods, the filament treated by the present apparatus gave uniform knitted goods, this was not the case for filaments which had not been airtreated. Further, when the knitted goods were dyed with an acid dye, it was found that the knitted goods obtained from the filaments according to the present invention were dyed uniformly, while the knitted goods obtained from the filaments which were not blown by air formed uneven dyeings which approximately corresponded to an irregularity in crimp.

What we claim is:

1. An apparatus for developing crimps on self-crimpable conjugated filaments held under a controlled slight tension comprising heating means, means for passing said filaments through said heating means so that said crimps are developed, feed roller means for feeding said filaments to said heating means at a given rate, delivery roller means located to receive said filaments from said heating means for delivering the crimped filaments at a rate lower than said given rate, and air blower means located intermediate said feed and said delivery roller means and positioned for causing an air stream to impinge on said filaments from one direction perpendicular to the path of said filaments thereby causing said filaments to laterally deviate from said path.

2. The apparatus according to claim 1 wherein said blower means is located between said heating means and said delivery roller means.

3. The apparatus according to claim 1 wherein said blower means comprises a tubular bod having an air inlet means and air exhaust means at opposite ends thereof, said filaments passing diametrically through said body perpendicular to the axis of the air passing therethrough, and means to force air into said air inlet means.

4. The apparatus according to claim 3, wherein the dimensions of said tubular body and said air exhaust outlet are such that the length of the filaments impinged by said air and caused to laterally deviate is in the range of 3 cm. to 30 cm.

References Cited UNITED STATES PATENTS 3,167,847 2/1965 Gonsalves 2872 X 3,238,590 3/1966 Nicita et -al 281 3,329,757 7/1967 Johnson 264282 3,296,681 1/1967 Lopatin 2862 X 3,299,485 1/1967 Hills et a1 2872 X LOUIS K. RIMRODT, Primal Examiner.

U.S. Cl. X.R. 2862 

